Leading machine tool manufacturers and research institutions have been working on the subject of “virtual machine tools” for a number of years. A key aspect of such virtual machines is associated with the manufacturing process, where interaction between the tool and workpiece is simulated and visualized graphically in 3D. Modern systems reproduce all the moving machine kinematics including material removal during the manufacturing process on the workpiece as a result of machining using the tool.
For example, in EP 1 901 149 B1 the applicant describes a device and a method for simulating a sequence for machining a workpiece in a machine tool, which is designed to reproduce as comprehensively as possible not only all machining operations on the workpiece itself, but also to simulate and reproduce the peripherals of the machine tool including the tool changer, workpiece changer, workspace, etc., in as realistic a holistic depiction as possible.
In machine tool applications, virtual machines usually consist of components on the control side and components on the system side, where the control-side components include the human machine interface (HMI) in the form of the control desk and monitor, the numerical control core, i.e., the control instructions which are predefined by a numerical control (NC) program, and the programmable logic controller (PLC), i.e., the machine-specific controller that usually controls mechanically regulated circuits including additional attachments such as tool changers, supply of cooling water, etc., and corresponding drive controllers, while system-side components specifically include drive systems including their kinematic and kinetic behavior (resilience, thermal behavior) and associated control assemblies, pneumatic/fluid systems, work and spindle kinematics including their geometric representation, work fixtures and tools, workpieces, and material-removal processes carried out herewith.
In many virtual machines, only parts of these components are materialized; additional components are shown in a few cases, such as the geometric representation of an external automation unit.
An important aim of the simulation process to date has been to run through the machining/movement sequences of a real process on the simulation platform in real time in the same steps as in the real application. This made it possible to obtain valuable information concerning the machining sequence, which could actually be expected, e.g., when commissioning a new machine tool or when setting up the machine tool. During this operation, the simulation processing speed may be slowed down to permit more accurate observation or even sped up depending on the performance of the simulation platform.
The simulation speed and thus the ability to obtain a rapid impression of a specific work process beforehand, e.g., regarding the absence of collisions, is currently substantially limited in existing simulation platforms by the capacity of the hardware used, acceleration only being achievable by increasing the clock frequency and integration of new hardware functions still only being achievable to a limited extent in the meantime. On the other hand, machining and movement operations are becoming increasingly complex with advanced machine tool developments, which thus imposes limits on a holistic approach to a virtual machine.
Realization of this fundamental problem is the starting point for the present disclosure, the object of which is to provide a method and a system for simulating a work process in a machine tool using a virtual machine that permits a higher simulation speed.